By John Jesitus
Although many forms of botulinum toxin available worldwide function similarly, the products are not interchangeable, as they have different protein sizes, diffusion characteristics, potencies and effects, says Fredric S. Brandt, MD, a Coral Gables, Fla., dermatologist.
In addition to Botox (onabotulinumtoxinA, Allergan) and Dysport (abobotulinumtoxinA, Medicis), there’s PurTox (Mentor), for which data have been submitted to the Food and Drug Administration, Brandt says. Xeomin (incobotulinumtoxinA, Merz) is FDA-approved for therapeutic and aesthetic indications, and RT001 (botulinumtoxinA, Revance) is a topical gel currently under investigation.
All varieties of botulinum toxin A contain the same 150 kilodalton active molecule, Brandt says. All presently FDA-approved botulinum toxins also include nonactive complexing proteins including hemagglutinin and nontoxic nonhemagglutinin proteins.
Botox surrounds the 150 kDa active molecule with 900 kDa of complexing proteins. "Dysport has less of the nonactive proteins than Botox does," he says. Botox includes no sugar, although Dysport includes lactose and Xeomin includes sucrose.
[Source: Modern Medicine/Dermatology Times]